1
use super::{FeedbackMessageType, PayloadType, RtcpHeader, RtcpPacket};
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use super::{RtcpType, Ssrc};
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4
/// Picture loss indicator.
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#[derive(Debug, Clone, PartialEq, Eq)]
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pub struct Pli {
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    /// Sender of this feedback. Mostly irrelevant, but part of RTCP packets.
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    pub sender_ssrc: Ssrc,
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    /// The SSRC this picture loss indication is for.
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    pub ssrc: Ssrc,
11
}
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13
impl RtcpPacket for Pli {
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    fn header(&self) -> RtcpHeader {
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        RtcpHeader {
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            rtcp_type: RtcpType::PayloadSpecificFeedback,
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            feedback_message_type: FeedbackMessageType::PayloadFeedback(
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                PayloadType::PictureLossIndication,
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            ),
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            words_less_one: (self.length_words() - 1) as u16,
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        }
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    }
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    fn length_words(&self) -> usize {
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        // header
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        // sender SSRC
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        // media SSRC
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        3
29
    }
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31
    fn write_to(&self, buf: &mut [u8]) -> usize {
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        self.header().write_to(&mut buf[..4]);
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        buf[4..8].copy_from_slice(&self.sender_ssrc.to_be_bytes());
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        buf[8..12].copy_from_slice(&self.ssrc.to_be_bytes());
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        12
36
    }
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}
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impl<'a> TryFrom<&'a [u8]> for Pli {
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    type Error = &'static str;
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    fn try_from(buf: &'a [u8]) -> Result<Self, Self::Error> {
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        if buf.len() < 8 {
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            return Err("Pli less than 8 bytes");
45
        }
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        let sender_ssrc = u32::from_be_bytes([buf[0], buf[1], buf[2], buf[3]]).into();
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        let ssrc = u32::from_be_bytes([buf[4], buf[5], buf[6], buf[7]]).into();
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        Ok(Pli { sender_ssrc, ssrc })
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    }
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}